Today the 12th annual challenge will be held with 423 competitors set to take to the Oreti River with 2000 people likely to attend the event in some capacity.

In 2001, when the club held the first event of its type in New Zealand, just seven business entered in the eights racing.

Eleven years on 33 eights will today take on the challenge and a further 11 quads have also entered.

It is the biggest corporate rowing event in New Zealand and has attracted a crew from Dunedin this year.

A corporate rowing regatta was scheduled for Dunedin this year but there were just two entries and one ended up pulling out.

The Waihopai Rowing Club had capped entries at 32 eights but Dunedin engineering firm Spiire asked if it could come south and compete.

John O'Connor, who has been one of the key organisers since Waihopai started it in 2001, said yesterday he was pleased with how it had grown in Southland.

"There are corporate regattas right throughout the country, mainly due to stuff I've passed on to other areas, but the Dunedin one hasn't really caught on mainly because they don't make it a separate regatta, they try and incorporate it with a club regatta they hold. You really must make sure you look after these people," O'Connor said.

The Waihopai Rowing Club uses the regatta as a way to promote the sport but also as the club's main annual fundraiser.

The club is expected to raise about $20,000 from the 2012 regatta which will go towards the club's ongoing cost, most notably boats.

O'Connor said the $20,000 seemed a lot but it was a massive exercise putting on the regatta.

"There's a heck of a lot of volunteer hours go into it. It wouldn't be able to be put out on a commercial footing," he said.

As well as the volunteers coaching and running the event, it is also financially successful for the club because many businesses support the fundraiser by providing services or equipment free or at a discounted cost.

Vodafone has come on board as the major sponsor for the regatta.

O'Connor said there had already been some incidents during training, with one of the crews running into a bridge, a team member from one boat getting flung out after catching a crab, and also a quad on three occasions tipping out together.

"It's supposed to be a team-building exercise and, you know, with the weather and trying to get people rowing together, it's all part of the challenge. That's why we call it the Corpor8 Challenge because it's not easy, but I think people think it will be and come up short when they realise there is actually a bit more to this rowing game than we thought."